Change SigninClient::CreateGaiaAuthFetcher return type to unique_ptr

ios/chrome/browser/signin/signin_client_impl.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef IOS_CHROME_BROWSER_SIGNIN_SIGNIN_CLIENT_IMPL_H_
 #define IOS_CHROME_BROWSER_SIGNIN_SIGNIN_CLIENT_IMPL_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
@@ skipping 36 matching lines @@
   net::URLRequestContextGetter* GetURLRequestContext() override;
   bool ShouldMergeSigninCredentialsIntoCookieJar() override;
   bool IsFirstRun() const override;
   base::Time GetInstallDate() override;
   bool AreSigninCookiesAllowed() override;
   void AddContentSettingsObserver(
       content_settings::Observer* observer) override;
   void RemoveContentSettingsObserver(
       content_settings::Observer* observer) override;
   void DelayNetworkCall(const base::Closure& callback) override;
-  GaiaAuthFetcher* CreateGaiaAuthFetcher(
+  std::unique_ptr<GaiaAuthFetcher> CreateGaiaAuthFetcher(
       GaiaAuthConsumer* consumer,
       const std::string& source,
       net::URLRequestContextGetter* getter) override;
 
   // KeyedService implementation.
   void Shutdown() override;
 
   // Returns a string describing the chrome version environment. Version format:
   // <Build Info> <OS> <Version number> (<Last change>)<channel or "-devel">
   // If version information is unavailable, returns "invalid."
@@ skipping 33 matching lines @@
   SigninErrorController* signin_error_controller_;
   std::list<base::Closure> delayed_callbacks_;
 
   std::unique_ptr<gaia::GaiaOAuthClient> oauth_client_;
   std::unique_ptr<OAuth2TokenService::Request> oauth_request_;
 
   DISALLOW_COPY_AND_ASSIGN(SigninClientImpl);
 };
 
 #endif  // IOS_CHROME_BROWSER_SIGNIN_SIGNIN_CLIENT_IMPL_H_